1999 Mazda Protege won’t start…Help

Hey I need some help yesterday on my way home my battery light was coming on and off at speeds above about 50 km/h tgis was cuasing my car to bog out and try and stall I got a new battery thinking that would be the issue and later after hooking it up my head lights will come on but it won’t turn on my dash lights or radio and won’t crank at all I’ve checked fuses and nothing I started it this morning with the old battery to pull into my shop so I tired putting the old battery back in and same results headlights on but nothing else I am wondering what my issue you could be maybe a faulty ground wire I’m not sure maybe try replacing my battery terminal clamps
 

pcb

The Diagram Dude
:
2002 MP5
When my battery light was flickering, it was the alternator that was bad.
(I have a 2002 Protege5. Your car is probably similar.)
 
Okay I will get another fuse and disconnect alternator and see if the fuse doesn’t blow right away I am looking do a short in the system right now
 

pcb

The Diagram Dude
:
2002 MP5
Also I have a 1.6 L does that have the same alternator as a 2.0

I'm not not sure, but I don't think so.
The alternator on my car is controlled by the ECU. (The regulator is in the ECU, not in the alternator.)

On my car, the battery light flashing, means that there is something wrong with the electric system in general, not just the battery specifically.

I had my battery light flicker when my alternator went bad and started putting out 17.5 volts and way too much current.
I had to turn on all my electrical loads to bring down the voltage to get it to the shop.
The alternator also shorted out internally and drained the battery while sitting overnight and I needed a boost to get it started.
 
I'm not not sure, but I don't think so.
The alternator on my car is controlled by the ECU. (The regulator is in the ECU, not in the alternator.)

On my car, the battery light flashing, means that there is something wrong with the electric system in general, not just the battery specifically.

I had my battery light flicker when my alternator went bad and started putting out 17.5 volts and way too much current.
I had to turn on all my electrical loads to bring down the voltage to get it to the shop.
The alternator also shorted out internally and drained the battery while sitting overnight and I needed a boost to get it started.
I’m gonna do some testing to figure out if it’s in the alternator for sure along with check to see if the wire is damaged if it is the problem and the wire is intact and fine my alternator will be replaced that would make sense why my car was trying to die on me well driving it home with the battery light coming on
 
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I'm not not sure, but I don't think so.
The alternator on my car is controlled by the ECU. (The regulator is in the ECU, not in the alternator.)

On my car, the battery light flashing, means that there is something wrong with the electric system in general, not just the battery specifically.

I had my battery light flicker when my alternator went bad and started putting out 17.5 volts and way too much current.
I had to turn on all my electrical loads to bring down the voltage to get it to the shop.
The alternator also shorted out internally and drained the battery while sitting overnight and I needed a boost to get it started.
So I have now tested it seem to be my alternator I unplugged the connections to it and put a new fuse in and it didn’t blow the fuse like last time but for some reason now when I turn the key over with the alternator in plugged everything turns on high beam wipers rad fans ect. And won’t turn of if I turn key to start you can hear the starter trying to go so I have ordered the new alternator in but I’m still not 100% that it needs to be replaced
 
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pcb

The Diagram Dude
:
2002 MP5
Your battery may be partially depleted and not able to deliver enough power to operate the starter motor.

Try charging the battery if you can, and try it again.
 
So I have put a new alternator in and when I hook my battery up again it still blows my 100 amp fuse I only hav wine left to get it start and can’t afford another one blowing
 

pcb

The Diagram Dude
:
2002 MP5
It sounds like you have a positive wire shorting to ground.

Check the fat positive wire that goes from your alternator to your battery.

See if the insulation is worn through and the wire inside is touching the frame of the car somewhere.


A bad ground would have no current flow.
A dead short will blow the main fuse.

Disconnect the battery and check the resistance between positive and negative battery wires.

Try disconnecting things and pulling fuses to trace the wire to find the short.

Check the resistance between ground and positive of the alternator and starter motor.


Somewhere, you've got a positive wire going straight to ground.
 

pcb

The Diagram Dude
:
2002 MP5
It seems that you aren't blowing the main fuse until your alternator is connected.
So disconnect the wires from your alternator and start there.


With the wires disconnected from the alternator, check the resistance from the big positive output post on the alternator to the frame of the car.

Then plug in the smaller control wire (if your alternator has one) and check the resistance again.

Something is shorting out somewhere around your alternator.


Remember to have your battery removed (or fully disconnected) when you check for resistance with your ohmeter, or you'll blow the fuse in your ohmeter.


Touch the positive and negative lugs from the battery together after they are both disconnected from the battery to drain any power from your ECU that stores memory.
 

pcb

The Diagram Dude
:
2002 MP5
Did the 100 amp main fuse blow as soon as you connected the battery, or after you turned the key and tried to start the car?
 
Did the 100 amp main fuse blow as soon as you connected the battery, or after you turned the key and tried to start the car?
As soon as I connected the battery I also took out the entire harness and checked every wire they seem all good and everything works fine with the alternator disconnected I even replaced the alternator with a brand new one and it’s still a dead shirt at the alternator
 

pcb

The Diagram Dude
:
2002 MP5
I test the alternator with an ohm reader to check the circuit and the new alternator is fine but the old one reads resistance


If you read 0 ohms from the positive output post on your alternator and the metal case, that's wrong.

That is a dead short.

Your old one reading resistance is what your supposed to read but it sounds like the regulator is screwed up in your old alternator.


I think that you've got a faulty new alternator.


There have been guys with my car (Protege5) that had to install 4 alternators before they got one that worked.

Rebuilds can be a crap shoot.


This is the info for the alternator on my car.
It's a bit different in that the regulator is in the ECU and not built into the alternator.

I don't know about the 1999 Protege?


Screenshot_20221203-160905_Acrobat for Samsung.jpg
Screenshot_20221203-160929_Acrobat for Samsung.jpg


This is a link to the Factory Service manual for my car.

It may be of some use to you, but I don't know how the 1999 Protege is different?

 
So essentially my regulater is inside my alternator this is also my second new one I have put in now I just don’t understand why it’s still a dead short but the wire also runs striaght back to my fuse box and joins in with the negative side of the battery terminal clamps and runs to my main fuse connect to the fuse box and the only thing I can source it back to is once again alternator so should I bring this one back in again and get another one?
 

pcb

The Diagram Dude
:
2002 MP5
So essentially my regulater is inside my alternator this is also my second new one I have put in now I just don’t understand why it’s still a dead short but the wire also runs striaght back to my fuse box and joins in with the negative side of the battery terminal clamps and runs to my main fuse connect to the fuse box and the only thing I can source it back to is once again alternator so should I bring this one back in again and get another one?

That doesn't sound right that the wire goes to the negative of the battery, unless it is a ground wire that's going to ground on the alternator?

Maybe the fuse is in the ground wire instead of the positive wire?
I dunno?

But, if you can install your old alternator and it Doesn't blow the fuse, then I'm pretty sure that you've had two faulty new alternators.

Your old alternator was sort of working if the rpms were low enough.

So if you can install it without blowing the fuse, then I think your replacement alternators are faulty.

Maybe bring your ohmeter to the parts store and test the alternator right at the store?
 
Last edited:

pcb

The Diagram Dude
:
2002 MP5
Make sure that the connector from the positive output terminal isn't touching the metal case of the alternator when it's attached.

Maybe it needs a rubber spacer?
I'm just guessing.


Screenshot_20221203-222855_Acrobat for Samsung.jpg
 
So I have checked the alternator to see if the wire was making contact it is I don’t think it’s the alternator because it is reading no resistance when I put it on the post and on the metal of the alternator